Peel pears and cut in half lengthwise. Trim out cores and place cut side down in baking dish.

In a small saucepan, combine sugar and 1/2 cup (125 mL) of the vinegar. Bring to a boil over medium-high heat, stirring until sugar is dissolved. Boil, without stirring, for about 8 min or until syrup turns a golden caramel colour. Remove from heat. While whisking, pour in remaining vinegar then quickly pour over pears in dish.

Roast pears, turning once, for 15 to 20 min or until pears are easily pierced with the tip of a knife. Let cool to lukewarm in syrup.

Meanwhile, line eight 1/2 cup to 3/4 cup (125 to 175 mL) ramekins or custard cups with a square of plastic wrap. In a bowl, fold Canadian Blue cheese into Canadian Mascarpone; season to taste with pepper.

Drain syrup from pears into a measuring cup; set syrup aside. Cut pears crosswise into thin slices. Arrange enough slices in each ramekin to cover bottom, overlapping slightly. Divide cheese mixture among ramekins, packing lightly; top with remaining pear slices. Cover and refrigerate for at least 1 hr or for up to 2 days.

Meanwhile, whisk mustard into reserved syrup; gradually whisk in oil until blended. If dressing is too thick, whisk in up to 2 tbsp (30 mL) hot water. Season to taste with salt and pepper. (Dressing can be covered and refrigerated for up to 2 days.)

About 30 min before serving, let cheese tortas and dressing, if necessary, stand at room temperature to remove the chill. To serve, in a large bowl, toss salad greens with half of the dressing. Divide greens among serving plates. Unmold tortas and place one on each salad. Drizzle with remaining dressing, to taste, sprinkle with pecans and season with salt and pepper.